Autocross Tire Guide: From All-Seasons to R-Comps
No single upgrade will improve your autocross times more than tires. Not suspension. Not alignment. Not a limited-slip differential. The patch of rubber between your car and the pavement determines the absolute limit of what your car can do in a corner, and in autocross — where the entire event is corners — tires are everything.
The good news is that SCCA classing rules are designed so that the cars most people own can be competitive on street-legal tires. You don't need R-compounds to be fast in Street class. Understanding the tire rules for your class, picking the right tire, and learning to drive on it consistently will get you further than anything else you can bolt on.
Why Tires Matter More Than Almost Any Other Upgrade
Autocross is a traction-limited sport at virtually every skill level up through advanced. In a 60–90 second course with 30–50 transitions, your tires are constantly at or near their grip limit. Every corner entry, every rotation, every acceleration point depends on traction — and traction is a function of the tire compound, the contact patch area, and how well the tire is loaded through suspension geometry.
A stock Miata on Bridgestone RE71RS tires will absolutely demolish the same Miata on all-season tires driven by an equally skilled driver. The grip difference between a quality all-season and a 200TW performance tire is enormous — we're talking 20–30% more lateral acceleration capacity. That's not a marginal improvement. That's a completely different car.
If you're building an autocross car and have a limited budget, spend it on tires first. A $700 set of RE71RS or RT660 tires will give you more improvement per dollar than any suspension modification, any alignment, or any power upgrade. This is not an opinion — it's physics.
How to Read UTQG Ratings
UTQG stands for Uniform Tire Quality Grading, a federal system the NHTSA requires on all passenger tires sold in the United States. It appears as three numbers/letters on the tire sidewall, like: 200 A A
- Treadwear (first number): A relative rating of expected tread life compared to a reference tire (rated 100). A 200TW tire should last roughly twice as long as the reference. A 100TW tire lasts half as long. For competition purposes, this number is also a rough proxy for grip — lower TW numbers generally mean stickier compounds. Note that UTQG testing is not standardized across manufacturers, so a Bridgestone 200TW and a Yokohama 200TW are not directly comparable in terms of actual life.
- Traction (letter grade A, B, C): Wet stopping performance in a straight line on specified test surfaces. A is best. This is not a measure of lateral grip or cornering traction — don't use it to compare tires for autocross purposes.
- Temperature (letter grade A, B, C): Heat resistance at high sustained speeds. A is best. Again, this measures straight-line thermal stability, not autocross performance.
For SCCA Solo competition, the treadwear number is what matters. Street and Street Touring classes require a minimum 200TW tire.
Tire Categories for Autocross
Autocross tires fall into four rough categories, listed from most street-friendly to most track-focused:
All-Season / UHP All-Season
Factory tires on most cars. Typically 400–600TW. Acceptable for your first few events while you learn the sport. Limiting factor quickly becomes the tire's inability to build consistent heat and grip. Not competitive in any serious class. Examples: Michelin CrossClimate2, Continental ExtremeContact DWS06+.
200TW Extreme Performance Summer (200TW)
The competitive class for SCCA Street and Street Touring. These tires have a UTQG treadwear rating of exactly or just above 200, making them eligible for all Street-class competition while remaining street-legal. This is the most important tier for the vast majority of SCCA Solo competitors. See our 200TW tire comparison for in-depth analysis of the top picks.
Max-Performance Non-200TW Summer
Tires like the Michelin Pilot Sport Cup 2 and the Continental ExtremeContact Force that have treadwear ratings below 200TW. These are legal for street use but not eligible for SCCA Street/Street Touring classes due to the 200TW rule. They fall into Prepared or Modified class for SCCA purposes, or are run in open class events. Grip is significantly higher than 200TW tires, but tread life is very short.
R-Compound (DOT Race Tires)
Tires like the Hoosier A7, Toyo Proxes RR, and Hankook RS4. These carry a DOT street-legal rating but are purpose-built race tires with very low TW ratings (typically 40–100). Allowed in SCCA Prepared and Modified classes, and in some Time Trial categories. Not legal for Street or Street Touring. Dramatically faster than 200TW tires, but expensive, wear quickly, and very heat-sensitive.
SCCA Solo Tire Rules by Class
| SCCA Class | Min Treadwear | R-Comps? | Notes |
|---|---|---|---|
| Street (SS, AS, BS, CS, DS, ES, FS, GS, HS) | 200TW | No | Must meet 200TW UTQG; some regions require Tire Rack approved list |
| Street Touring (STR, STX, STH, STS, STF) | 200TW | No | Same 200TW rule; more car mod freedom |
| Street Modified (SM, SMF) | None | Yes | R-comps allowed; very open class |
| Prepared (CP, DP, EP, FP, HP) | None | Yes | R-comps allowed; class-specific size limits apply |
| Modified (AM, BM, CM, DM, EM, FM) | None | Yes | Very open rules; R-comps standard |
| CAM (CAM-C, CAM-S, CAM-T) | 200TW | No | Same 200TW rule as Street; verify current CAM rules |
| CAMC (CAM Challenge) | None | Yes | Check current rulebook |
SCCA Solo rules are updated annually. Class structures and tire eligibility rules do change. Always verify your class rules with the current SCCA Solo Rules document before purchasing tires for a competition event. The summary above is accurate as of the 2025-2026 season but may not reflect future changes.
The Three Competitive 200TW Tires
In the 200TW category, three tires dominate the competitive autocross field in 2025-2026: the Bridgestone Potenza RE71RS, the Yokohama ADVAN A052, and the Falken Azenis RT660. Each has different strengths. Here's a brief overview — see our dedicated 200TW tire comparison article for a thorough breakdown.
- Bridgestone Potenza RE71RS: The long-running benchmark. Extremely consistent grip across varying temperatures, good wet performance for the category, slightly more tread life than the A052. Available in the widest range of sizes. The default pick for most Street class drivers.
- Yokohama ADVAN A052: The current leader in peak grip in back-to-back testing on cool surfaces. Aggressive compound that rewards a fast, smooth driving style. Heat-sensitive — performance drops in very hot conditions or after multiple back-to-back runs. Shorter tread life than the RE71RS or RT660.
- Falken Azenis RT660: The newest of the three, and arguably the best all-around value: best tread life of the group, very competitive lap times, excellent wet performance. The current default recommendation for drivers who want performance and longevity.
What About Non-200TW Performance Tires?
Several high-performance street tires fall below the 200TW threshold and are therefore not eligible for SCCA Street or Street Touring classes. The most notable examples are:
- Michelin Pilot Sport Cup 2 / Cup 2 R: Among the fastest street-legal tires made. Legal for Prepared and Modified classes. Not legal for Street/ST. Exceptional grip, very short life, very expensive.
- Continental ExtremeContact Force: Aggressive compound, below 200TW in some sizes. Check specific size UTQG ratings before purchasing for competition.
- Toyo Proxes R888R: Borderline 200TW — some sizes are rated above 200, some below. Excellent grip and a well-regarded R-compound-adjacent tire. Verify your specific size's UTQG before entering Street class.
R-Compound Tires
R-compounds (R-comps) are DOT street-legal tires built with race-car compounds. The most commonly run examples in SCCA Prepared and Modified classes are the Hoosier A7, Toyo Proxes RR, and Hankook Ventus RS4. These tires offer dramatically more grip than 200TW tires — often 25–40% more lateral acceleration — but are not class-legal for Street or Street Touring competition.
If you're running Street or ST class, don't worry about R-comps. The whole point of those classes is to be competitive on street-legal 200TW tires. If you're running Prepared or Modified and shopping for R-comps, the Hoosier A7 is the dominant choice for most applications, with the Toyo RR as a strong alternative with slightly longer life.